The invention relates to flushing devices for marine propulsion devices such as an outboard motor. Generally, a flushing device provides a means to introduce fresh cold water to the water intake port of an outboard motor, thereby enabling the motor to be cleaned or flushed with clean water without the necessity of removing the motor from the boat. Prior flushing devices for outboard motors are disclosed in Benson U.S. Pat. No. 2,611,631 issued Sept. 23, 1952 and in Guhlin U.S. Pat. No. 3,002,488 issued Oct. 3, 1961.